1. Field of the Invention
The present invention relates to a conveyance system incorporated in various photographic treatment apparatuses for an exposed but undeveloped photosensitive material, and particularly to an improved conveyance system suitably incorporated in an automatic developing apparatus in which a series of developing steps comprising developing, bleaching, fixing, stabilizing, hardening, and others, accompanied by water washing interposed between any two steps as required, and processing steps for drying as required, are performed for the exposed long-length photosensitive material such as photographic printing paper which is originally in a form of a roll and is comparatively wide, but has a tendency of losing its rigidity against warping as it becomes wet with treatment liquid.
2. Description of the Prior Art
Until this time, a variety of photographic treatment equipment and apparatus for photosensitive material with conveyance systems incorporated therein have already been developed and some have been put to practical use, wherein said photographic treatment equipment and apparatus are constructed such that a series of photographic treatments such as developing treatments comprising developing, bleaching, fixing, stabilizing, hardening and others are performed not only for a long length photosensitive material but also for short photosensitive sheet material, accompanied by water washing interposed between any two treatment steps as required, and drying subsequently carried out therefor, while the photosensitive material to be treated is guided by means of a guide member with guiding grooves formed at both side edges thereof without the necessity for a leader, trailer or conveyance belt means.
However, the disadvantages of the conventional conveyance system incorporated in the photographic treatment equipment or apparatus are, that due to the arrangement of a number of conveyance rollers throughout the conveyance passage with guiding grooves formed at both side edges thereof for the travelling photosensitive material and due to any minor relative speed difference between the respective conveyance rollers as well as between any one of the conveyance rollers and auxiliary roller disposed in the guide-in portion to the guide groove, the guide-out portion from said guide groove or the conveyance direction changing section tends to cause undesirable wrinkles or injured traces on the travelling photographic printing paper, while developing treatment is performed for the travelling printing paper, because this kind of long length photographic printing paper is in a form of a roll and is comparatively wide, but has a tendency of losing its ridigity against longitudinal warping as it is conveyed through the photographic treatment equipment or apparatus and gets wet with treatment liquid. In the worst case, the traveling photographic printing tears. Thus it is natural that the need for eliminating the aforesaid disadvantages of conventional photographic treatment equipment and improving its operational performance is increasingly voiced by many operators of conventional photographic treatment equipment. Lately it has been suggested that as manufacturers of photographic treatment equipment, we should be ready to substantially increase operational efficiency of this equipment, in response to the recent widespread use of cameras.